POS0770 INCREASED RISK OF FRACTURE, RECURRENT FRACTURE AND POST-FRACTURE MORTALITY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS: A POPULATION-LEVEL, LINKED DATA STUDY
Authors: W. Raymond, C. Inderjeeth, D. Preen, H. Keen, J. Nossent
Journal: Annals of the Rheumatic Diseases (2022)

Background Systemic lupus erythematosus (SLE) patients have higher fracture risk, driven by primary (chronic inflammation) and secondary (glucocorticoids treatment) osteoporosis. However, there is limited data on fracture recurrence and post-fracture mortality in this vulnerable population. Objectives To describe the association between systemic lupus erythematosus (SLE) and the risk of fracture(s), 5- and 10-year recurrent fracture(s), and 5-year post-fracture mortality, compared to hospital-based controls in Western Australia (WA) from 1980 - 2014. Methods Population-level cohort study of SLE patients (n=2,440, 28,002 person-years) and general population comparators (controls) (n=10,220; 161,392 person-years) identified within the Western Australia (WA) Rheumatic Disease Epidemiological Registry (WARDER). SLE patients 18-80 years old (identified by ICD-9-CM: 695.4, 710.0, ICD-10-AM: L93.0, M32.0) and controls were nearest matched (5:1) for age, sex, Aboriginality, and temporality. Follow-up was from timezero (index SLE hospitalisation) to fracture-related hospitalisation, death or 31/12/2014. Using longitudinal linked health data we determined the relative risk of (low impact) fracture-related hospitalisations (after excluding for traumatic and external factors, such as, falls from more than standing height and transport accidents), 5- and 10-year recurrent fractures, and 5-year post-fracture mortality between SLE patients and controls with multivariate Cox proportional hazards regression models from 1980-2014. Results Compared to general population controls, SLE patients had higher multivariate-adjusted risk (aHR 2.44, 95%CI 2.08, 2.87; P&lt;0.01) of fractures during follow-up. SLE patients had higher fracture risk regardless of sex, Aboriginality, age group (highest in those &lt;50 years of age), or study period (2000-2014: aHR 1.83, 95%CI 1.32, 2.55; P&lt;0.01). SLE patients had higher risk of hand, wrist and forearm fractures (aHR 1.95), vertebral fractures (aHR 5.73), hip fractures (aHR 1.83), and lower limb, ankle and foot fractures (aHR 2.14). Similarly, SLE patients had higher risk of both 5- (aHR 2.89) and 10-year (aHR 3.00) fracture recurrence, which held across sub-group analyses and remained high in the most recent 2000-2014 period (aHR 2.84 and aHR 3.04, respectively). SLE patients had higher (aHR 1.56, 95%CI 1.16, 2.09; P&lt;0.01) risk of 5-year post-fracture mortality, which held for female SLE patients (aHR 1.45), those ≥70 years-old (aHR 1.72), and remained in the 2000-2014 period (aHR 1.57). Conclusion SLE patients have an increased risk of fractures, 5- and 10-year recurrent fractures, and 5-year mortality post-fracture compared to controls from the general population. After adjustment for conventional risk factors, these associations remained unchanged in the most recent period (2000-2014). This study highlights the need for improved primary prevention of a first fracture event in SLE patients. Acknowledgements The authors wish to thank the staff at the Western Australian Data Linkage Branch and Emergency Department Data Collection, Hospital Morbidity Data Collection, Western Australian Cancer Registry, and Death Registrations. The authors wish to thank the Australian Co-ordinating Registry, the Registries of Births, Deaths and Marriages, the Coroners, the National Coronial Information System and the Victorian Department of Justice and Community Safety for enabling COD URF data to be used for this publication. Disclosure of Interests None declared